TWI597042B - Endoscopic with distance measuring function and distance measuring method - Google Patents

Description

Endoscope and ranging method with ranging function

The invention relates to the distance measuring technology of the endoscope, in particular to an endoscope and a distance measuring method with a distance measuring function using optical interference technology.

Ranging methods for endoscopes are known, for example, from WO 2015/098353 A1, which discloses a technique for performing ranging using a movable joint and a visual axis. Although this technique can perform distance measurement, it is structurally required to use solid joint joints, and it is movable, so it is complicated in control and measurement.

U.S. Patent No. 2010/0324366 A1 discloses another endoscope mirroring technique which mainly utilizes a measuring light to project a predetermined shape on the surface of an object to be measured, and then shape the shape. After taking the image, calculate the size of the shape, and finally calculate the distance and angle between the endoscope and the measured object.

This case will propose a technique for measuring the distance by means of optical interference/diffraction on the endoscope, which is different from the prior art.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide an endoscope having a ranging function that provides a technique for measuring distance by means of optical interference/diffraction, which is different from the prior art.

In order to achieve the above object, the present invention provides an endoscope having a distance measuring function, comprising: a host connected to an observation unit by a tube body, the observation unit mainly having a tube and being disposed in the seat tube a single-wavelength light source, a diffraction grating, an image capturing unit, and a light-shielding partition; the seat tube has an opening at the front end; the single-wavelength light source is disposed in the seat tube for passing through the opening Generating a predetermined wavelength of light forward; the diffraction grating has a plurality of slits disposed in the seat tube and between the single-wavelength light source and the opening to generate single-wavelength light passing through the slits Diffraction phenomenon, and projecting on an object to be tested through the opening to display a zero-order bright spot, and one of the positive first-order bright spots and one negative first-order bright spot respectively on the two sides of the zero-order bright point, wherein the single wavelength The vector angle between the light source emitted to the zero-order bright point and the adjacent bright spots on both sides is calculated according to the predetermined wavelength and the slit width of the diffraction grating; the image capturing unit is disposed in the seat tube and has An image sensor and a lens group, wherein the lens group has a lens magnification, and the image capturing unit obtains an image by taking an image forward through the opening, and the image capturing range of the image capturing unit covers the zero order a bright spot and the positive first-order bright spot and the negative first-order bright spot; the light-shielding partition is disposed in the seat tube, and the image capturing unit is separated from the single-wavelength light source and the diffraction grating to make the single wavelength The single-wavelength light emitted by the light source is not reflected or refracted inside the seat tube to the image capturing unit; the host has a computing unit having a standard number of bright pixels, and the computing unit has three kinds of arithmetic logic The first operation logic is to calculate a distance between the brightness of the lens and the number of pixels of any bright spot on the image and the number of pixels of the standard bright spot to obtain a distance magnification; the second operation logic is The distance magnification is used to calculate the distance between two adjacent bright spots on the image, thereby obtaining the actual distance between two adjacent bright spots projected on the object to be tested; the third operation logic is borrowing The actual distance between adjacent two bright spots with the vector angle calculated a distance between the zero-order diffraction grating with the highlights.

Accordingly, the present invention is based on the technique of optical interference/diffraction, and the distance of the object to be measured is measured by judging the diffraction bright spot, which is different from the prior art.

Still another object of the present invention is to provide a method of ranging from an endoscope that provides a technique for measuring distance by means of optical interference/diffraction, which is different from the prior art.

In order to achieve the above object, the present invention provides a method for ranging of an endoscope, comprising the following steps: A) emitting a predetermined wavelength of light by a single wavelength light source disposed in an observation unit at the front end of a tube of an endoscope, Projecting through a diffraction grating to an object to be measured, and projecting a zero-order bright spot on the surface of the object to be tested and a positive first-order bright spot and a negative first-order bright spot respectively on both sides of the zero-order bright spot, wherein The vector angle emitted by the single-wavelength light source to the zero-order bright point and the adjacent bright spots on both sides is calculated according to the predetermined wavelength and the slit width of the diffraction grating; B) the image capturing unit of the endoscope Taking an image of the object to be measured, and obtaining an image including the zero-order bright spot, the positive first-order bright spot, and the negative first-order bright spot; and C) calculating the image by using a computing unit of the host of the endoscope The number of pixels of the zero-order bright point, the positive first-order bright point, and the negative first-order bright point, refer to the number of standard bright-point pixels preset by the calculating unit, according to a first operation logic and the image-taking unit itself The head magnification is used to calculate a distance magnification; and the second operation logic is used to calculate the distance magnification and the distance between two adjacent bright spots on the image, thereby obtaining a projection onto the object to be tested. The actual distance between two adjacent bright points; finally, according to a third operation logic, the actual distance between the two adjacent bright points and the angle between the vectors are calculated, thereby obtaining the diffraction grating and the zero-order bright point the distance.

Thereby, the foregoing ranging method of the present invention is based on the optical interference/diffraction technique, and the distance of the object to be measured is measured by judging the diffraction bright spot, which is different from the prior art.

10‧‧‧Endoscope with ranging function

11‧‧‧Host

12‧‧‧Computation unit

121‧‧‧First operational logic

122‧‧‧Second operational logic

123‧‧‧ Third operational logic

21‧‧‧ tube body

31‧‧‧ observation unit

32‧‧‧ seat tube

33‧‧‧ openings

34‧‧‧Single wavelength light source

36‧‧‧Diffraction grating

361‧‧‧ gap

38‧‧‧Image capture unit

381‧‧‧Image sensor

382‧‧‧ lens group

39‧‧‧Lighting partition

99‧‧‧ objects to be tested

D‧‧·Distance between the diffraction grating and the zero-order bright spot

I‧‧‧ images

L0‧‧‧ zero-order highlights

L1‧‧‧ first-order highlights

L-1‧‧‧ negative first-order highlights

S‧‧‧ gap width

Θ‧‧‧ vector angle

△X‧‧‧The actual distance between two adjacent bright spots on the object to be tested

ΔX’‧‧‧The distance between two adjacent bright spots on the image

10’‧‧‧Endoscope with ranging function

12’‧‧‧Computation unit

121’‧‧‧First operational logic

122’‧‧‧Second operational logic

123’‧‧‧ Third operational logic

124’‧‧‧ fourth operational logic

34'‧‧‧ single wavelength source

36'‧‧‧Diffractive grating

42'‧‧‧ collimation mirror

D1‧‧‧Distance between the zero-order bright spot and the positive first-order bright spot

The distance between the d2‧‧ ‧ zero-order bright spot and the negative first-order bright spot

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of a first preferred embodiment of the present invention.

Figure 2 is a partial cross-sectional view showing a portion of the components of the first preferred embodiment of the present invention, showing the internal state of the viewing unit.

Figure 3 is a schematic view of the components of the first preferred embodiment of the present invention showing a diffraction grating.

Figure 4 is a block diagram of a circuit of a first preferred embodiment of the present invention.

Figure 5 is a schematic view showing the operation of the first preferred embodiment of the present invention.

Figure 6 is a schematic view showing another operation of the first preferred embodiment of the present invention.

Figure 7 is a partial cross-sectional view showing a part of the components of the second preferred embodiment of the present invention.

Figure 8 is a block diagram of a circuit of a second preferred embodiment of the present invention.

Figure 9 is a schematic view showing the operation of the second preferred embodiment of the present invention.

In order to explain in detail the technical features of the present invention, the following preferred embodiments are described with reference to the accompanying drawings, wherein: FIG. 1 to FIG. 6 are provided to provide a first preferred embodiment of the present invention. An endoscope 10 having a distance measuring function is mainly composed of a main body 11, a tube body 21 and an observation unit 31, wherein the main body 11 is connected to the observation unit 31 by the tube body 21, the observation The unit 31 mainly has a tube 32, a single-wavelength light source 34 disposed in the seat tube 32, a diffraction grating 36, an image capturing unit 38, and a light shielding partition 39.

The seat tube 32 has an opening 33 at its front end.

The single-wavelength light source 34 is disposed in the seat tube 32 for emitting light of a predetermined wavelength λ forward through the opening 33. In actual implementation, the single-wavelength light source 34 may be a laser light source, an infrared light source or an ultraviolet light source, or a visible light source of a specific wavelength may be selected; in addition, the single-wavelength light source 34 may be selected from a light-emitting diode in the selection of components. The LED (LED), the LED can be directly disposed in the seat tube 31; the single-wavelength source 34 can also be selected from a combination of an optical fiber and an illuminating source, and the illuminating source is disposed on the host 11 And placing the optical fiber on the main body 11 and passing through the tubular body 21 so that the end is located in the seat tube 31. Since it is a well-known technique to set the optical fiber to guide the light emitted by the light source, the detailed setting method will not be described again, and it is not allowed to express it in the figure.

The diffraction grating 36 has a plurality of slits 361. The diffraction gratings 36 are disposed in the seat tube 32 and located between the single-wavelength light source 34 and the opening 33 to cause diffraction of single-wavelength light passing through the slits 361. The phenomenon is displayed on the object to be tested 99 through the opening 33 to display a zero-order bright point L0, and one of the first-order bright point L1 and one negative first-order bright point L-1 respectively located on the two sides of the zero-order bright point L0. The vector angle θ emitted by the single-wavelength light source 34 to the zero-order bright point L0 and the adjacent bright spots L1, L-1 on both sides is calculated according to the predetermined wavelength λ and the slit width s of the diffraction grating 36. Got it. The vector angle θ is obtained by the width s of the slit 361 and the wavelength λ of the single-wavelength light by the equation s sin θ = λ . Since the slits 361 are actually a lot of dense and difficult to express clearly in the drawings, the slits 361 of the diffraction grating 36 in the drawing are displayed for convenience of display, and are not Draw according to the actual scale.

The image capturing unit 38 is disposed in the seat tube 32 and has an image sensor 381 and a lens group 382. The lens unit 382 has a lens magnification m, and the image capturing unit 38 is oriented through the opening 33. The image is taken in front to obtain an image I, and the image capturing range of the image capturing unit 38 covers the zero-order bright point L0 and the positive first-order bright point L1 and the negative first-order bright point L-1.

The light shielding plate 39 is disposed in the seat tube 32, and the imaging unit 38 is separated from the combination of the single wavelength light source 34 and the diffraction grating 36, so that the single wavelength light emitted by the single wavelength light source 34 is not It will be reflected or refracted inside the seat tube 32 to the image taking unit 38.

The computing unit 12 has a computing unit 12 having a standard number of bright pixels P, and the computing unit 12 has three kinds of computing logic 121, 122, 123, and the first computing logic 121 is based on the lens magnification m and The number of pixels ΔP(x) of any bright spot on the image I and the number of standard bright pixel P are calculated to obtain a distance magnification M; the second operation logic 122 is obtained by the distance magnification M. Calculating the distance ΔX′ between the two adjacent bright spots on the image I (in the embodiment, the unit of the distance is in the form of a millimeter, the same applies hereinafter), and then the two adjacent objects projected on the object to be tested 99 are obtained. The actual distance ΔX between the bright points; the third operation logic 123 is to calculate the diffraction grating 36 and the zero-order bright point L0 by the actual distance ΔX between the two adjacent bright points and the vector angle θ. The distance between D. Wherein, since the endoscope is inspecting the object 99 to be tested, the viewing distance is short, generally not exceeding 20 cm, so that the observation unit 31 of the endoscope is moved anyway within the viewing distance, and the single-wavelength light is projected on the object. The size of the bright spot on the object to be tested 99 hardly changes, so the manufacturer can set a standard condition (for example, a fixed distance), and the number of pixels of the single-wavelength bright spot taken under the standard condition is defined. The number of pixels P is highlighted for this standard.

In the first embodiment, the first operation logic 121 defines the lens magnification as m, and the distance magnification is M, and the number of pixels of any bright spot on the image I is ΔP(x), The number of standard bright spot pixels is P, and the distance magnification M is obtained by calculation by the following formula (1).

Therefore, when the lens magnification m and the standard bright spot pixel number P are fixed values, the change of the pixel number ΔP(x) of any bright spot on the image I changes the value of the distance magnification M.

In the second operation logic 122, the distance between two adjacent bright spots on the image I is defined as ΔX′, and the actual distance between two adjacent bright points is defined as ΔX, and the following formula is used. (2) Perform a calculation to obtain the actual distance ΔX between adjacent bright spots.

△X=△X ' ×M.........(2)

Thereby, the actual distance ΔX between the two adjacent bright spots can be calculated by obtaining the distance ΔX' between the two adjacent bright spots on the image I and matching the distance magnification M.

As for the third operation logic 123, the vector angle is defined as θ, and the distance between the diffraction grating 36 and the zero-order bright point L0 is defined as D, and the calculation is performed by the following formula (3). The distance D between the diffraction grating 36 and the zero-order bright point L0.

In the case where the diffraction grating 36 is regarded as the observation unit 31, the distance D can be regarded as the distance between the observation unit 31 and the object 99 to be tested.

The architecture of the first embodiment has been described above. Next, the ranging method of the endoscope provided by the present invention is combined with the architecture of the first embodiment to describe the ranging operation.

Referring to FIG. 1 to FIG. 6 , the method for measuring the distance of the endoscope of the present invention comprises the following steps:

A) the light of the predetermined wavelength λ is emitted by the single-wavelength light source 34 disposed in the observation unit 31 at the front end of the tube 21 of the endoscope, and is projected to the object 99 to be measured via the diffraction grating 36, and the object to be tested is to be tested. The surface of the object 99 projects the zero-order bright point L0 and the positive first-order bright point L1 and the negative first-order bright point L-1 respectively located on the two sides of the zero-order bright point L0, wherein the single-wavelength light source 34 is emitted to the zero-order bright point The vector angle θ between L0 and its bright spots on both sides is calculated based on the predetermined wavelength λ and the slit width s of the diffraction grating 36.

B) Taking the object 99 to be measured by the image capturing unit 38 of the endoscope to obtain the image I including the zero-order bright point L0, the positive first-order bright point L1, and the negative first-order bright point L-1.

C) calculating, by the calculation unit 12 of the host 11 of the endoscope, the number of pixels of the zero-order bright point L0, the positive first-order bright point L1, and the negative first-order bright point L-1 in the image I, refer to the calculation The number of the standard bright pixels P set by the unit 12 is calculated according to the first operation logic 121 and the lens magnification m of the image capturing unit 38 itself; and the second operation is performed according to the second operation The logic 122 calculates the distance magnification M and the distance ΔX′ between two adjacent bright spots on the image I, thereby obtaining the actual distance between two adjacent bright spots projected on the object 99 to be tested. X; finally, according to the third operation logic 123, the actual distance ΔX between the two adjacent bright points and the vector angle θ are calculated, thereby obtaining the distance between the diffraction grating 36 and the zero-order bright point L0. D. The calculation formulas of the first, second, and third operation logics 121, 122, and 123 can be referred to the foregoing first embodiment.

It can be seen from the above that the technique of measuring the distance by means of optical interference can accurately measure the distance between the observation unit 31 of the endoscope and the object 99 to be tested, and the technical features of the present invention are different from the prior art. .

Referring to FIG. 7 to FIG. 9 again, an endoscope 10' having a ranging function according to a second embodiment of the present invention is mainly similar to the first embodiment disclosed above, except that: The second embodiment further includes a collimating mirror 42', and the computing unit 12' further includes a fourth operational logic 124'.

The collimating mirror 42' is disposed between the single-wavelength light source 34' and the diffraction grating 36'. The single-wavelength light emitted by the single-wavelength light source 34' penetrates the collimating mirror 42' and is irradiated thereto. Diffraction grating 36'. The collimating mirror 42' is for adjusting the light shape of the single-wavelength light so as to be in a state of being non-diffused in parallel.

The fourth operation logic 124' is mainly caused by the distance d1 between the zero-order bright point L0 and the positive first-order bright point L1 relative to the distance d2 between the zero-order bright point L0 and the negative first-order bright point L-1. The difference value is calculated as an inclination angle α of the surface of the object 99 to be measured with respect to the vertical plane of the single-wavelength light projecting the zero-order bright point L0.

In the fourth operation logic 124', the distance between the zero-order bright point L0 and the positive first-order bright point L1 is defined as d1, and the distance between the zero-order bright point L0 and the negative first-order bright point L-1 is D2, the inclination angle of the surface of the object 99 to be measured with respect to the vertical plane of the zero-order bright point L0 direction of the single-wavelength light projection is α, and the inclination angle α is obtained by calculation by the following formula (4).

Thereby, the inclination angle α can be obtained, and then the user can judge whether the surface of the object to be tested 99 is not perpendicular to the observation direction and is inclined.

When the first, second, and third arithmetic logics 121', 122', 123' are executed, since the surface of the object to be tested 99 is inclined, it is only necessary to set the zero-order bright point L0 in the image with the The distance between the first-order bright point L1 and the distance between the zero-order bright point L0 and the negative first-order bright point L-1 are averaged, which can be used as the distance between two adjacent bright points, thereby obtaining the operation The distance D between the diffraction grating 36' and the zero-order bright point L0.

The remaining structure of the second embodiment and the achievable functions are the same as those of the first embodiment, and will not be further described.

10‧‧‧Endoscope with ranging function

31‧‧‧ observation unit

32‧‧‧ seat tube

33‧‧‧ openings

34‧‧‧Single wavelength light source

36‧‧‧Diffraction grating

38‧‧‧Image capture unit

381‧‧‧Image sensor

382‧‧‧ lens group

39‧‧‧Lighting partition

99‧‧‧ objects to be tested

D‧‧·Distance between the diffraction grating and the zero-order bright spot

L0‧‧‧ zero-order highlights

L1‧‧‧ first-order highlights

L-1‧‧‧ negative first-order highlights

Θ‧‧‧ vector angle

ΔX‧‧‧The actual distance between two adjacent bright spots on the object to be tested

Claims (13)

An endoscope with a distance measuring function includes: a main body connected to an observation unit by a tube body, the observation unit mainly has a tube and a single wavelength light source and a diffraction disposed in the seat tube a grating (diffraction grating), an image capturing unit and a light shielding partition; the seat tube has an opening at the front end; the single wavelength light source is disposed in the seat tube for emitting a predetermined wavelength of light through the opening The diffraction grating has a plurality of slits, and the diffraction grating is disposed in the seat tube and located between the single-wavelength light source and the opening to cause a diffraction phenomenon of single-wavelength light passing through the slits, and through the opening Projecting on an object to be measured to display a zero-order bright spot, and a positive first-order bright spot and a negative first-order bright spot respectively on both sides of the zero-th order bright spot, wherein the single-wavelength light source is emitted to the zero-order bright spot and The vector angle between adjacent bright spots on both sides is calculated according to the predetermined wavelength and the slit width of the diffraction grating; the image capturing unit is disposed in the seat tube and has an image sensor and a lens group. among them The lens unit has a lens magnification, and the image capturing unit obtains an image by taking an image forward through the opening, and the image capturing range of the image capturing unit covers the zero-order bright spot and the positive first-order bright spot and the negative one a light-blocking partition, disposed in the seat tube, separating the image capturing unit from the combination of the single-wavelength light source and the diffraction grating, so that the single-wavelength light emitted by the single-wavelength light source does not The interior of the seat tube is internally reflected or refracted to the image capturing unit; the host has a computing unit having a standard number of bright pixels, and the computing unit has three kinds of arithmetic logic, and the first computing logic is The lens magnification is calculated by the number of pixels of any bright spot on the image and the number of standard bright pixels, and a distance magnification is obtained; the second operation logic is to calculate the two on the image by the distance magnification. The distance between adjacent bright spots, and then the actual distance between two adjacent bright spots projected on the object to be tested; the third operation logic is the actual distance between the two adjacent bright points Combining the vector angle to calculate a distance between the diffraction grating and the zero-order bright point; wherein, in the first operation logic, the lens magnification is defined as m, and the distance magnification is M, and the image is on the image. The number of pixels of any bright spot is ΔP(x), and the number of standard bright spot pixels is P, and the distance magnification M is obtained by calculation by the following formula (1); Thereby, when the lens magnification and the number of standard bright spot pixels are fixed values, the change in the number of pixels of any bright spot on the image changes the value of the distance magnification. An endoscope having a ranging function according to claim 1 of the patent application, further comprising: a collimating mirror disposed between the single-wavelength light source and the diffraction grating, the single-wavelength light emitted by the single-wavelength light source The collimating mirror is penetrated to the diffraction grating, and the single-wavelength light is collimated by the action of the collimating mirror to be in a non-diffusion state. According to the second aspect of the patent application scope, the endoscope has a ranging function, wherein: in the second operation logic, the distance between two adjacent bright spots on the image is defined as ΔX′, and two adjacent The actual distance between the bright points is ΔX, and the actual distance ΔX between the two adjacent bright points is obtained by the following formula (2); ΔX = ΔX ' × M....... By formula (2), the actual distance between the two adjacent bright points can be calculated by obtaining the distance between two adjacent bright spots on the image and matching the distance magnification. According to the third aspect of the patent application scope, the endoscope has a ranging function, wherein: in the third operation logic, the vector angle is defined as θ, and the distance between the diffraction grating and the zero-order bright point is defined as D, and calculating by the following formula (3) to obtain the distance between the diffraction grating and the zero-order bright point; An endoscope having a ranging function according to claim 1 of the patent application, wherein: the calculating unit further comprises a fourth operation logic, wherein a distance between the zero-order bright point and the positive first-order bright point is relative to the zero And a distance difference between the step bright point and the negative first-order bright point, and calculating an inclination angle of the surface of the object to be tested relative to a vertical plane of the single-wavelength light projecting the zero-order bright point direction. According to the fifth aspect of the patent application scope, there is an endoscope with a ranging function, wherein: in the fourth operation logic, a distance between the zero-order bright point and the positive first-order bright point is defined as d1, and the zero-order bright point is The distance between the negative first-order bright points is d2, and the inclination angle of the surface of the object to be tested relative to the vertical plane of the single-wavelength light projecting the zero-order bright point direction is α, and is calculated by the following formula (4). Obtaining the tilt angle α; The inclination angle α can be obtained by the above formula (4). An endoscope having a ranging function according to claim 1 wherein the single wavelength source is selected from a light emitting diode (LED) or a combination of an optical fiber and an illuminating light source. A method for ranging of an endoscope includes the following steps: A) emitting a predetermined wavelength of light by a single-wavelength light source disposed in an observation unit at the front end of a tube of an endoscope, and waiting through a diffraction grating Measuring the object projection, and projecting a zero-order bright spot on the surface of the object to be tested and a positive first-order bright spot and a negative first-order bright spot respectively on both sides of the zero-th order bright spot, wherein the single-wavelength light source is emitted to the zero-order light point The angle between the bright spot and the adjacent bright spot on both sides is calculated according to the predetermined wavelength and the slit width of the diffraction grating; B) taking the image of the object to be measured by the image capturing unit of the endoscope, and obtaining An image including the zero-order bright point, the positive first-order bright point, and the negative first-order bright point; and C) calculating, by the computing unit of the host of the endoscope, the zero-order bright point in the image, the positive The first-order bright point and the number of pixels of the negative first-order bright point refer to a standard bright-point pixel number preset by the calculating unit, and calculate a distance according to a first operation logic and a lens magnification of the image capturing unit itself. amplification And calculating a distance between the distance magnification and the distance between two adjacent bright spots on the image according to a second operation logic, thereby obtaining an actual distance between two adjacent bright spots projected on the object to be tested; Finally, according to a third operation logic, the actual distance between the two adjacent bright points and the angle of the vector are calculated, thereby obtaining a distance between the diffraction grating and the zero-order bright point; wherein: the first operation logic In the middle, the lens magnification is m, and the distance magnification is M, the number of pixels of any bright spot on the image is ΔP(x), and the number of standard bright pixels is P, and by the following Equation (1) is calculated to obtain the distance magnification M; Thereby, when the lens magnification and the number of standard bright spot pixels are fixed values, the change in the number of pixels of any bright spot on the image changes the value of the distance magnification. . According to the method for measuring the endoscope according to Item 8 of the patent application scope, wherein: in the second operation logic, the distance between two adjacent bright spots on the image is defined as ΔX′, and two adjacent bright spots are defined. The actual distance between them is ΔX, and the actual distance ΔX between two adjacent bright points is obtained by the following formula (2); ΔX=ΔX ' ×M........ Equation (2) Thereby, the actual distance between the two adjacent bright points can be calculated by obtaining the distance between two adjacent bright spots on the image and matching the distance magnification. According to the method for measuring the endoscope of the ninth application patent, wherein: in the third operation logic, the vector angle is defined as θ, and the distance between the diffraction grating and the zero-order bright point is defined as D And calculating by the following formula (3) to obtain the distance between the diffraction grating and the zero-order bright point; According to the distance measuring method of the endoscope according to claim 8 , the calculating unit further includes a fourth operation logic, wherein the distance between the zero-order bright point and the positive first-order bright point is relative to the zero-order A distance difference between the bright point and the negative first-order bright point is calculated, and an inclination angle of the surface of the object to be tested relative to a vertical plane in which the single-wavelength light projects the direction of the zero-order bright point is calculated. According to the method for measuring the endoscope of the eleventh application patent, wherein: in the fourth operation logic, the distance between the zero-order bright point and the positive first-order bright point is defined as d1, and the zero-order bright point and the The distance between the negative first-order bright points is d2, and the inclination angle of the surface of the object to be tested relative to the vertical plane of the zero-order bright point is α, and is calculated by the following formula (4). The inclination angle α; The inclination angle α can be obtained by the above formula (4). According to the distance measuring method of the endoscope of claim 8, wherein the single wavelength source is selected from a light emitting diode (LED) or a combination of an optical fiber and an illuminating light source.